A fuel nozzle is essential to most fuel burners and consists of a device to prepare the fuel, gaseous or liquid, for efficient combustion. These devices have a variety of configurations, depending upon the physical characteristics of the fuel being consumed.
Almost exclusively, gaseous fuel nozzles consist of simple metering devices or orifices. Gas under its natural or supply system pressure is forced through the orifice, downstream of which is usually a tube to conduct the naturally aspirated mixture of fuel and entrapped air to a burner head. By contrast, liquid fuel nozzles typically use high fuel pressure and swirl and mechanical techniques to create a spray which is directed into the burner where it is mixed with a forced supply of air and burned. A disadvantage of prior art gaseous and liquid fuel nozzles is that they have functionally different designs for fundamentally different processes and therefore are not mutually interchangeable.
There is an increasing need for burners having multiple fuel capability, particularly those which can burn gaseous as well as liquid fuels. Moreover, there is a growing need for dual fuel burners for larger commercial or indistrial sized heating appliances, particularly in view of the increasing uncertainties about the availability of fuels. For example, a burner which can consume liquid fuels in a manner approximating gaseous fuels (i.e., natural convection combustion) is of particular interest since it can replace gas burners in applications which rely solely upon gaseous energy sources. In particular, gas burners for industrial processes such as boilers, hearths, heat treatment, and baking are candidates for dual fuel burners.
Accordingly, it is an object of this invention to utilize the characteristics of a pneumatic type atomizer to provide a simple burner which is capable of burning gaseous as well as liquid fuels and which has multiple nozzles or flame heads to increase the output of the burner assembly.
It is a further object of this invention to provide a burner which, in its simplest form, comprises a plurality of air-atomizing nozzles and sources of pressurized gas and liquid and gaseous fuels associated with each nozzle.
It is a still further object of this invention to provide a multi-flame fuel burner which will distribute heat evenly over the heat transfer surface.
Yet another object of this invention is to provide a multi-flame fuel burner which is naturally aspirating.
Still another object of this invention is to provide a multi-flame fuel burner which is cpable of cross-ignition among flame heads from a single ignited flame head.
Another object of this invention is to provide a multi-flame fuel burner which produces exceptionally clean and high temperature combustion products for application heating efficiency.
Still further objects and advantages of this invention will become apparent upon reading the following specification and claims, taken in conjunction with the accompanying drawings.